Rear-end loader for tractors



Jan. 6, 1953 c. B. RICHY REAR-END LOADER Foa TRAd'roRs 2 SHEETS--SHEET l Filed Sept. 8, 1949 i] INVENTOR. .QA f/ycf R/c//fr ArraR/vfy Jan. 6, 1953 c. B. ICHY 2,624,481

1 REAR-END LOADER' FOR TRAcToRs Filed sept. s, 1949 2 SHEETS-SHEET 2 IN VEN TOR. @MM/rf ,0a/fr Patented Jan. 6, 1953 UNiTED srArss garant oFFicE REAR-END LOADER FR TRCTRS Clarence B. Richey, Royal Oak, Mich., assigner to Dearborn Motors Corporation, Highland Park, Mich., a corporation of Delaware Application September 8, 1949, Serial No. 114,646

(Cl. 2id-i410) i Claims. l

This invention relates to a loading or material handling device for tractors, and particularly to a loader adapted for mounting on the rear end of ra tractor of the type having power lifted, vertically swingable trailing hitch links.

A variety of rear end loader constructions have been heretofore disclosed in the patented art which utilize the power lifted trailing hitch links provided on several well-known makes of tractors to provide the lifting force for the boom of the loader device. A feature of lthis invention is the provision of an unusually simplified, yet sturdy and economically manufacturable construction for such a rear end loader. Another feature of this invention is the ease of mounting of implements, such as loaders, to the rear end of a tractor, which in a large measure is due to the assembly of substantially all of the principal components of the implement on a vertical frame structure which in turn is provided with suitable projections to permit such frame structure to be conveniently attached to existing connection points commonly provided on the rear axle and differential housing of well-known makes of tractors.

Still another feature of this invention is the provision of a special connecting linkage between the hydraulically liftable hitch links of the tractor and the pivoted boom of the loader such that the effective leverage arm of the lifting force applied to the loader boom is substantially greater during the initial upward movement of the loader boom than the effective leverage arm provided throughout the remainder of the lifting movement of the boom. Such desirable result is accomplished by a connecting linkfwhich shifts its eiective connection point to the boom inwardly relative to the pivotal axis of the boom as the boom is initially raised. Such construction has the advantage of providing the extra force needed at the .lowermcst positions lof the boom to free the load being lifted, and, by decreasing the effective leverage arm of the lifting force applied to the boom after it is initially raised, permits the boom to be raised to a greater height than would be possible with a conventional linkage.

Accordingly, it is an object of this invention to provide an improved rear end loader construction for tractors of the type having power lifted,

vertically swingable hitch links trailinglypivoted to the rear portions of the tractor.

A further object of this invention is to provide a rear end loader construction which may be quickly and conveniently assembled to commercially available tractors by utilizing connection points already provided on such tractors.

lversely spaced points as by the pins lla.

Still another object of Ythis invention is to provide an unusually strong and sturdy loader construction which may nevertheless be economically manufactured.

An important object of this invention is to provide an improved connecting linkage between the pivoted boom of a tractor mounted loader and a power lifted hitch link commonly provided on various commercial tractors which will effect a shifting of the point of application of lifting force to the boom as the boom is raised to provide a greater effective leverage arm during the initial raising movement of the boom than during the remainder of its vertical movement.

The specic nature of this invention, as well as other objects and advantages thereof, will become apparent to those skilled in the art from the following detailed description, taken in conjunction with the attached sheets of drawings on which, by way of preferred example only, are illustrated two embodiments of this invention.

On the drawings:

Figure 1 is a side elevational View of a loader embodying this invention shown in assembled relationship to a well-known tractor of the type having power lifted trailing hitch links.

Figure 2 is a sectional view of the loader only taken along the plane 2 2 of Figure 1.

Figure 3 is an elevational View of the loader only taken from the plane 3-3 of Figure 1.

Figure l is a partial sectional view of the loader only taken along the plane 3 4 of Figure 1.

Referring to Figure l, the numeral I0 indicates the rear end portion of a tractor of well-known construction. Such tractor includes a rear axle casing l l which supports a rear axle (not shown) and which in turn mounts a pair of rear Wheels I2. On the bottom central portion of the rear axle casing il, a clevis type trailer hitch I3 is provided and at the top central portion of casing l l a pair of laterally spaced ears or brackets la are provided which are suitably apertured to receive a transverse pin l5 which normally is employed to mount an angular link I by 'which the compression link of the three link hitch is conventionally attached to the tractor.

The two lower links ll of the three link hitch are pivctally mounted to the casing ll at trans- Such links are raised and lowered by a conventional hydraulic mechanism (not shown) provided on the tractor and which connects to the links l'l through lifting links i3 respectively.

All of the construction thus far mentioned constitutes conventional elements provided on a Wellknown type of tractor and hence description in greater detail is believed to be unnecessary.

The rear end loader embodying this invention is primarily assembled to a frame construction which, as best shown in Figure 2, comprises a pair of plates 2| which are secured in spaced parallel relationship at their bottom ends by a horizontal plate 22 welded thereto, and near their centers by a generally U-shaped bracket 23 which has its bight portion welded to the plates 2| The horizontal plate 22 has a forwardly projecting portion 22a which, when the loader is assembled to the rear end of the tractor, projects into the clevis trailer hitch |3 and is suitably apertured to receive the hitch pin |3a. The arm portions 23al of U-shaped bracket 23 also project horizontally forward to engage the tractor bracket I4 and are suitably apertured to receive the angle link pin l5. The frame 20 is thus supported in a generally upright position at the rear end of the tractor and is substantially rigidly secured to the tractor.

Near the top central portions of the plates 2 l, a sleeve 24 is welded between the plates 2| and provides horizontal support for a pivot pin 25 which is keyed thereto by cotter pin 25a. .A boom 2E is provided which is of generally U-shaped configuration and has a pair of spaced projecting ears 2 welded to its bight portion and provided with bearings 27a to receive the ends of the pin 2E. The boom is thus mounted on the frame 2Q for swinging movements in a substantially vertical plane.

The free ends of the boom 213 are connected by a tubular cross piece 23a and platelike arms 23h project rearwardly therefrom as a substantial continuation of boom 25. Arms 25h provide a pivotal mountingT for a material handling or loading device 28 which may be either a bucket, a manure fork, a pallet carrier or any other type of loading container. The particular material container 28 shown in the drawings is of the type described and claimed in my copending application, Serial No. 114,645, filed on even date herewith, now Patent No. 2,597,374.

To effect the lifting of the boom 26 and hence of the material container 28, a linkage connection to the power lifted hitch links I1 is provided. In order to locate the effective lifting point on the links l! at a position close to the rear axle of the tractor, an angle bar 29 is attached to the end portion of each hitch link l? by a pin l'lb and extends forwardly along each hitch link with the horizontal 23a of each angle 23 overlying the top face of the respective hitch link H. At their forward extremities, the angles 29 are interconnected by a transversely extending rod 3S which has reduced diameter end portions 36a journaled in suitable apertures provided in the forward ends of the vertical flanges 29h of angles 29. A connection link 3| is pivotally mounted on each reduced diameter portion 33a of rod 33, and these links provide the lifting connection between the power lifted hitch links l1 and the loader boom 26. Connection links 3| are of triangular platelike configuration, and the top portions of links 3| project into the interior of a channel shaped element 32 which is secured to the underside of each arm portion of the boom 2G. A pair of pins 33 are mounted in the channel element 32 in transverse relationship and are respectively located at substantially different spacings along the boom 26 with respect to the pivotal axis of such boom.

As will be later described, the pins 33 function as abutment surfaces which are successively engaged by corresponding spaces provided on connecting links 3| so as to effect a reduction of the effective leverage arm of the lifting force applied to the boom 26 after the boom is initially raised.

As best shown in Figure 1, each plate 3| has a slot 3| a formed in its upper end which receives the innermost pin 33. Each connecting link 3| also has a notch portion 3lb located rearwardly and downwardly from the slot portion 3 |a which receives the outermost pin 33 in the lowermost position of boom 26 and hitch links I1. The slot 3|@ is so proportioned that no lifting action is exerted by the walls of the slot on the innermost pin 33 until the boom 26 has been initially raised a predetermined distance. Hence, during such initial raising of the boom 26 by hitch links I1, all of the lifting force is transmitted to boom 26 through the medium of the outermost abutment pin 33. After the boom 26 has been raised slightly, the lower end wall of slot 3 la moves into engagement with the innermost abutment pin 33 and transfers the effective lifting force on the boom 26 to this innermost pin where, of course, the effective leverage arm of such lifting force is substantially reduced over that available at the location of the outermost abutment pin 33. In this manner, it is apparent that a substantially greater lifting action is imparted to the boom 26 throughout its lower range of movement where normally a greater force is required in order to free the load being lifted.

It has been previously mentioned that the material receiving container 28 is pivotally attached to the ends of the boom 26. To maintain the container 28 in an upright position, a trip dump linkage is provided comprising a V-shaped elongated link 35 pivotally attached to the top end of the container 28 and having its vertex end pivoted in toggle relationship to a pair of parallel short links 3S which are, in turn, pivoted to the top end of frame structure 20 by a pin 35a. To adjust the angularity of the container 28 in the dumped position, a plurality of holes 2lb are provided in frame plates 2| to be selectively used to mount pin 36a. 'I'he plates 2| of frame structure 2U have their top portions 2 la bent inwardly, as best shown in Figure 2, to snugly surround the short links 36. An operating handle 31 is secured to the vertex end of link 35.

Referring to Figure l, the dotted lines indica-te the positions of the loader elements when the boom 25 has been raised to a desired height for dumping the load. The handle 37 is then pushed rearwardly by the tractor operator to extend the toggle joint provided by links 35 and 36, and this action has the effect of pivoting the material receiving container 28 to dump the load out of its open rear end.

In some applications, the lifting effect exerted by the power lifted hitch links l1 may be insufficient for the loading job for which the equipment is designed. In such cases, it is desirable to provide an auxiliary hydraulic cylinder to supplement the lifting action of the hitch links Il. The loader embodying this invention conveniently permits such auxiliary cylinder to be attached in the manner illustrated in Figure 1 of the drawing. Thus, an auxiliary hydraulic cylinder 40 may have its one end portion pivotally mounted on the vertical frame structure 23 on a transverse pin 4| suitably mounted between the spaced plates 2|. The other end of the cylinder unit 4! is pivotally attached to the cross piece 26a provided on the ends of the arms of boom 26. A pair of spaced ears 42 may be conveniently welded to cross piece 26a to receive a pin 43 to provide such pivotal mounting. The cylinder unit is provided with pressured fluid through a hose type connection 40a. Such fiuid is preferably derived fromthe hydraulic system of the tractor so that the power lifting of the hitch links Il will be accompanied by the hydraulic actuation of cylinder 40.

From thel foregoing description, it is apparent that this invention provides an unusually simple, yet sturdy and rugged loader construction. When applied to the rear end of tractors of the type having power lifted trailing hitch links, the loader may be quickly attached to the tractor in less than a minute by utilizing conventional connection points already available on the tractor. In fact, the entire assembly operation involves no more than the insertion of four pins, respectively, the clevis hitch pin 13a, the angle connector pin I5, and the two pins Hb, respectively, provided in the ends of hitch link I1.

Furthermore, the feature of providing an increased effective lever arm for the lifting force on the boom during the initial raising movement of the lever arm very substantially increases the capacity of the loader and its adaptability to diicult loading situations where extra effort is required in the initial movement to free the loader,

while at the same time permitting a greater total raising movement of the loader boom.

It will, of course, be understood that many details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim:

l. A tractor mounted loader comprising a boom arm pivotally mounted on the tractor for vertical swinging movement, a power-lifted arm on the tractor, a connecting link between said arms, whereby said boom arm is lifted by said power arm, said connecting link having a pivotal connection to one of said arms, the other of said arms having a pair of spaced abutments thereon, and said connecting link having a pair of spaced surfaces thereon, one of said surfaces being engageable with one of said abutments during the initial raising movement of said arms and the other of said surfaces engaging the other of said abutments throughout the rest of the raising movement of said arms, thereby shifting the effective leverage arm of the lifting force applied to said boom arm as said power-lifted arm is raised.

2. In combination with a tractor having a rear axle and differential housing, trailer' hitch means at the bottom of said housing, bracket means at the top of said housing, and a vertically swingable power lifted link trailingly pivoted to said housing, a loader comprising a vertical frame element having -a rst horizontal projection connected to said bracket means, a second horizontal projection on said frame element connected to said trailer hitch means, a boom pivoted to a medial portion of said vertical frame element in overlying relationship to said power lifted link, a connecting linkage between said boom and said power lifted link, whereby said boom is raised and lowered by vertical movements of said power lifted links, said connecting linkage including means defining a pair of spaced pivot points at which force is applied to the boom, and the means being effective to shift the effective point of application of lifting force to Said boom from one of said points to the other as said power lifted link is raised.

3. A rear end loader for tractors having `a rear axle casing and hydraulically liftable hitch links trailingly pivoted to said casing, comprising, in combination, a boom, means for supporting said boom on said tractor casing for pivotal movement in a. vertical plane, a connecting link having one end portion adapted for connection to one of said hitch links, a pair of abutments on said boom respectively located at different distances from the pivotal axis of said boom, and a pair of spaced surfaces on said connecting link successively cooperating with said abutments as said hitch link is raised, one of said surfaces being engageable with one of said abutments during the initial raising movement of said hitch links and the other' of said surfaces engaging the other of said abutments throughout the rest of the raising movement of said hitch links, thereby changing the effective leverage of the lifting force imparted to said boom by said hitch link.

4. A rear end loader for tractors having a rear axle casing and hydraulically liftable hitch links trailingiy pivoted to said casing, comprising, in combination, a boom, means for supporting said boom on said tractor casing for pivotal movement in a vertical plane, a connecting link havingone end portion adapted for connection to said hitch link, a ypair of -transverse pins supported on said boom, said pins being respectively disposed at different distances from the pivotal axis of said boom, said connecting plate having a slot receiving the innermost transverse pin and a notch engageable with the outermost transverse pin in the lowermost positions of the said hitch link, said slot being constructed and arranged to contact said innermost transverse ,pin in lifting relation only after said hitch link has been lifted upwardly a predetermined distance, thereby decreasing the effective leverage of the lifting force applied to said boom after said boom has been initially raised.

CLARENCE B. RICHEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,364,121 Arps Dec. 5, 1944 2,441,070 Hoover May 4, 1948 2,449,212 Fraga Sept. 14, 1948 2,465,476 Pokorny et al. Mar. 29, 1949 2,496,874 I-Iolopainen Feb. 7, 1950 2,501,797 Ulrich Mar. 28, 1950 2,543,496 Holopainen Feb. 27, 1951 

